Machine for making metal tubing.



PATENTED JAN. 21, 1908.

E. T. GREENPIELED. MACHINE FOR MAKING METAL TUBING.

APPLICATION FILED NOV. 6. 1905.

2 SHEETS-SHEET 1.

Y E N R 0 TI: T A r PATENTED JAN. 21, 1908.

I B. T. GREBNFIELD. MACHINE FOR MAKING METAL TUBING.

APPLICATION FILED NOV. 6, 1905.

2 SHEBTSSHEET 2.

INVENTOR WITNESSES joints each with another, such I so EDWIN r. GREENFIELD, OF K AMEsHA, NEW YORK.

MACHINE FOR MAKING METAL TUBING.

Specification of Letters Patent. Application filed November 6. 1905. seen No. 286.069.

' Patented Jan. 21, 1908.

To all whom it may concern: I

Be it known that I, EDWIN T. 'GREEN- FIELD, a citizen of the United States, residing at Kiamesha, in the county. of Sullivan and State of New ,York, have invented certain new and'useful Improvements in Machines for Making Metal 'Tubing, of which the following is a specification.

The object of my invention is to rovide a machine for ma flexible metal ic tubing by forming a plurality -of long strips of sheetmetal spirally one over another and breaking tubes being of use in manydifierent ways but particularly as conduits or armoring for electric conductors. Preferably the tubes are formed from two such sheet metal strips, and'for making such tubes, Iprovide a machine having a set of rotatable forming-rolls arranged to bend a strip of sheet-metal (as, for example, upon a mandrel) s irally to form a tube, and a second set of rotatable forming-rolls arranged to bend.

a second strip spirally about the tube formed by the first strip and strip bent thereby breaks joints with the first strip.

In the preferred form of my invention, the two strips of sheet-metal before being thus formed into a tube,- are acted upon by suita the spiral bending is efiected are preferably so arranged that adjacent edges of successive convolutions of the two layers of spirallyformedstrips are-substantially in contact so that the tu out its length and there are therefore no weak'points where the tube maybe morereadily punctured. The referred embodiment of my invention'is lus'tratedin'the accompanying draw- -i s in which igure 1 is a to view of'the machine, Fig. 2 is a view of the "eland forming-rolls in diagram, Fig. 3 is a vertical section and Fig. 4 an end view of themachine, Fig. 5 is a section showing the bearings for the two sets of formso displaced laterally from the first set of forming-rolls that the p e formed is of double the thick-' ness of one of the strips at all points through-' forming-rolls.

ingrolls and Figs. 6 and 7 are viewsof the die-rollers.

Referrin to the drawings,-A indicates a.

base or.-be -plate on which three standards B, C and D are erectedparallel with each other and a set of-rotatable forming-rollsE and Fare mounted in bearings between the middle one of the standards and each of the outer ones. Each of these standards comprise two base-blocks b and 1)? (Figs. 3 and 5) mounted in line witheach other and a hand c fastened at each end to one of the blocks 1) and b. Secured to the under side ofthe band- 0 above the base-blocks b and b are two blocks 6 and b The adjacent sides of the blocks 1;, 'b, b and b are lparallel-with each other and on each of .t sides is a tongue 1) running lengthwise there-. of, thus forming four guideways extendin radially from a commoncent'er and s aces apart equally. Mounted to slide bat: and forth in each of these guideways is a suitably grooved bearing d and screws (1 extend through threaded openings in the band 1 and a plate 0 uniting the base-blocks b and b by which the center. Four shafts '6, each carrying a forming-roll of the first set E are 'mounted for'rotation in the bearings d of standards B and O and shafts f each carrying. a formingroll of the second set F are similarly mounted in the. hearings in standards C-and D. The blocks b,;b', b

D are extended on the non-adjacent sides and are machined to form cylindricalsun faces each having a peripheral groove therein and each of these surfaces forms a bearing.

for a gear G to the side of which is secured a ring 9 extending into the peripheral grooveto positionthe gear. On the interior and exterior of each gear G beyond the end of the .bearing are formed gear-teeth, the exterior teeth meshing with those of-apower-driven gear and the interior teeth meshing with four pinionsH (Fig. 4), of one of the shafts e and f carrying the the standards B, O and D is a sleeve t and in the sleeve in standard Bis secured a mandrel the bearings d may be moved toward and b of-the standards B and each mounted on the end Mounted centrally. in each of ese parallelor more annular the tube is to be formed. These formingrolls are so constructed and positioned on the shafts e that the convex surfaces on each roll'are offset laterally by a definitev amount from those on the next succeeding roll around the mandrel I. The shaft e near which the stri of metal is introduced may, and prefera 1y does,-carry a roller-h and below this roller maybe mounted a guideplate h in which a roller 71, is pivoted directly under the slightly offset laterally from those on the I resent a concave exterior.

next succeeding roll. The shaft f near which the strip is introduced may be rovided with a guide-roller h and a plate ii, carrying a I 'de-roller k may be mounted directly be- I ow it.

Secured on the base A, as shown in Fig. 1, opposite the first set of forming-rolls E are bearings for two shafts j'each carrying a dieroller J and a gear y" by which the dieroller is driven from any suitable source of'power.

These die-rollers rotate one directly above.

the other and the periphery of the u per roller is somewhat concave and that o the lower one correspondingly convex (Figs. '1 and 7), so that a strip of metal' passing between them is given a transverse curvature after Which the strip passes to the first'set of forming-rolls where it is bent spirally into a tube, the transverse curvature effected by these rollers being such that the several con volutions of the tubes formed from the strip Mounted on ase A opposite the second set of formingrolls F are bearings for two shafts 7c each carrying a die-roller K and a gear k by which the die-roller is driven. These rollers also rotate one directly above the other and the upper one has 'a convex and the lower one a concave peri hery (Figs; 1, 2 and 6) so that a sheet-meta strip in passing between them is given a transverse curvature such that the convolutionsof the tube formed therefrom present, a convex exterior.

' In operatin the. machine, thegears j, k and G, G are riven from a suitable source of power thus driving the formin' -rollers and the die-rollers respectively T e end of a long strip M of sheet-meta (preferably steel) is introduced between the die-rollers J, J and as the strip asses between them it is bent to conform to t e shape of the peripheries of the rollers. Thestrip then passes'between the guide-rollers h and 72, under the mandrel I- and up between the mandrel and the form? ing-roll E at, the back of the machine.

The annular convex surface of this roll E engages the concave face presented by the strlp and presses the strip upon the man-- sheet-metal K, K, where it is bent to conform to the sursive 'convolutions being substantially in contact. The tube thus formed moves along the mandrel of itself so that the operation proceeds continuously. A second strlp N of asses between the die-rollers face of the rollers, then between (guide-rollers,- h and h, under the tube forme by the first stri and the mandrel inclosed thereby and etween the tube and the forming-roll F u of the second set at the back of the machine.

The annular concave surface on this roll engages the convex face of the strip as do those of the other rolls F to bend the strip upon the tube formed by the strip M, and the displacement laterally of the convex surfaces on each of the'fo rming-rolls relative to the next succeeding roll efiects a'spiral formation having adjacent edges of successive convolutions substantially in contact. The sec ond set F of forming-rolls is so displaced laterally from the first set E that the spirals of the second series break joints with; those of the first and the adjacent edges of two convolution's of the convex strip'lie in the depression at the middle of a convolution of the concave strip. The com leted .tube is moved along by the action of t e machine so that the operation is a continuous one. will be seen that-the construction of the machine permits of adjusting the bearings for the several shafts carrying the forming rolls radially so that the desired spacing of the rolls relatively to. the mandrel can be obtained.

tions of both the inner and outer series of spirals are substantially in contact as shown at the left of Fig. 1, the completed tube is of double the thickness of one, of the strips from which it is formed at all points throug out its length and is therefore of uniform strength. Moreover, I have found that where, as in the present case, the adjacent edges of the several strips are substantially in contact, there is less anger of disrupting the tube or armor formed thereby .whenflthe same is bent on a sharp curve. a curvature is given it there is little if any opening of the joints along the circumference o the curve.

What I claim is':

1. The combination of a mandrel, a set of fprming-rolls disposed about the mandrel for forming a strip spirally thereon, means for rotating said rolls, a second set of formingrolls for forming a second strip spirally about the first, said set of rollsbeing so displaced laterally from the first set that the strip formed thereby breaks joints with the first Where such tating the" second set "of rolls, as described.

set of ro strip, and means for rotating the second set of rolls, substantially as described.

2. The combination of a set of formingrolls disposed about an axis for forming a strip spirally, means for rotating said rolls, a second set of forming-rolls for forming a second strip spirallyabout the, first, said set of rolls being so displaced laterally from the first set that the strip formed thereby breaks joints with the first strip, and means forrosubstantially 3. The combination of a set of formingrolls having annular convex surfaces disposed about an axis for forming a strip spirally, means for rotating said rolls, a second set of forming rolls having annular concave surfaces for forming a second strip spirally about the first, said set of rolls being so displaced laterally from the first set that the of rolls being so displaced laterally from the first set that the strip'for'med thereby breaks joints with the first strip, and means for rotating the second set of rolls, substantially as' described.

5. The combination of a die for bending a:

strip, a set of forming rolls disposed about an axis for forming the strip spirally into a tube after it has been acted upon by said die, means for rotating said rolls, a second die for bending a second strip, a second set of form ing-rolls for forming said strip spirally about the first and breaking joints therewith after it has been acted upon by said die, and means for rotating said rolls, substantially as described, i

6. The combination'of a die for bending a strip, a mandrel, a set of formin 1 1 g.

annular convex surfaces disposed about the mandrel for forming the strip spirally thereon after it has been acted upon by said die, -means for rotating said rolls, a second die for bending a. second strip, a second set of forming-rolls having annular concave surfaces for forming said strip spirally about the .first and breaking joints therewith after it has been-acted upon by said die, and means for rotating said rolls,substantially as described.

7. The combination of a pair of die-rollers for curving a strip transversely, means for rotatingsaid rollers, a mandrel, a set of forming-rolls having annular convex surfaces disposed about the mandrel for forming the strip spirally thereon after it has been acted upon by said die-rollers, means for rotating said forming-rolls, a second pair of die-rollers for curving a second strip transversely, means for rotating said die-rollers, a second set of forming-rolls having annular concave surfaces for forming said second strip spirally about the first, said set of rolls being so displaced laterally from the first set that the strip formed thereby breaks jointswith the first strip, and means for rotating the second set of rolls, substantially as described.

8. 'The combination of a mandrel, a set of.

forming-rolls disposed about the mandrel for forming a strip spirally thereon, means for rotating said rolls, means for feeding a strip to the rolls, a second set of forming-rolls for forming a second strip spirally about the first, said set of rolls being so displaced laterally from the first set that the strip formed thereby breaks joints with the first strip,

means for feeding the second strip to said,

rolls, and means for rotatin the second set of rolls, substantially as descri ed.

This specification signed and witnessed this 31st day of October, 1905.

EDWIN T. GREENFIELD.

Witnesses:

S. O. EDMoNDs, D. S. EnMoNDs, 

